1. Technical Field of the Invention
This invention relates to radio telecommunication networks and, more particularly, to a system and method in a radio telecommunications network for automatically providing a roamer port number to a calling party.
2. Description of Related Art
Existing radio telecommunications networks provide local service to subscribers that are operating in the service area of their own service provider. When a subscriber roams to another (visited) network, however, long distance charges may be incurred. For example, a subscriber in the 514 area code of Montreal may roam to the 905 area code of Toronto. At that time, if a calling subscriber in Montreal calls the roaming subscriber at his 514 number, the roaming subscriber has to pay long distance charges equivalent to the long distance charge from Montreal to Toronto. Likewise, if a calling subscriber in Toronto calls the roaming subscriber at his 514 number, the calling subscriber has to pay long distance charges even though both subscribers are currently located in the same exchange.
In order to avoid long distance charges when both subscribers are located in the same exchange, roamer ports are implemented in each exchange. In the example above, if the calling subscriber in Toronto is aware that the roaming subscriber from Montreal is currently in Toronto, the calling subscriber first dials a local roamer port number. He then gets another dial tone, and he dials the telephone number of the roaming subscriber. The call is billed as a local call rather than a long distance call.
However, the calling subscriber in Toronto must be informed that the Montreal subscriber is in Toronto. If the Montreal subscriber knows he is going to Toronto, he can look up the Toronto roamer port number in the roamer port directory and call the Toronto subscriber and tell him the roamer port number. This manual process is cumbersome, however, especially if the Montreal subscriber plans to communicate with a large number of subscribers in Toronto.
Although there are no known prior art teachings of a solution to the aforementioned deficiency and shortcoming such as that disclosed herein, U.S. Pat. No. 5,513,247 to Mukerjee et al. (Mukerjee) discusses subject matter that bears some relation to matters discussed herein. Mukerjee discloses a call-handling method that determines when a roaming subscriber is in the same exchange as a calling subscriber, and automatically connects the call through the roamer port in a manner that is transparent to the subscribers. No long distance charges are incurred, but neither of the subscribers is informed of this fact. Therefore, they think that long distance charges are being incurred, and may unnecessarily cut the call short. In addition, the calling subscriber is not informed of the location of the called subscriber.
Review of the foregoing reference reveals no disclosure or suggestion of a method such as that described and claimed herein. In order to overcome the disadvantage of existing solutions, it would be advantageous to have a method of automatically informing the calling party that a called roaming subscriber is in the same exchange, and providing the appropriate roamer port number to the calling subscriber so that long distance charges can be avoided. The present invention provides such a method.